body {
  background-color: #000000;
}

.center-horizontal {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.center-vertical {
  margin: 0;
  position: absolute;
  top: 50%;
  -ms-transform: translateY(-50%);
  transform: translateY(-50%);
}

.center-vertical-horizontal {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}